Black screen at Windows load screen

The other day when I booted up my computer, it got as far as the Windows screen with the bar scrolling at the bottom, and then, when I should have gotten the welcome screen, my lcd monitor went black, with a no signal notice and went into standby. I could not get into Windows, even in safe mode. I did a full restore, and everything seemed to be going well, until I installed the ATi video drivers. The same problem started again, black screen, no signal at the Windows screen. Windows seems to be loading, I can hear the hard drive clicking and the Windows start up music is heard and finishes after the black screen.

Things I have tried to resolve this:

Did a full Windows restore.
Reloaded the video drivers, old and new, numerous times.
Tried the ram sticks one at a time, didn't find a problem with them.
Ran Memtest, no errors.
Took video card out and reseated. Replugged vid card power wire.
Took the audio card out and reseated.
All voltages seem to be okay in the bios, fans and hardware are running, so I think the power supply is okay.
No overclocking.
Don't see any problems in the Bios.
Cooling seems to be okay. No dust in heatsinks.
Windows loads okay in VGA mode.
I have .net installed.
I don't see any obvious burned spots on the video card or motherboard.
Done Google searches and found many with the same problem, but nobody seemed to have a fix. Accept buy nVidia.
Searched TechSpot.

The only thing I can think of that it might be after all this is the video card or the motherboard, but because of the driver issue, I'm leaning toward the video card, naturally the most expensive thing in the box.

Running now in VGA mode with no problem, accept the video of course, not much fun running in this oh so slow mode.

Any help will be very much appreciated.

XP SP 2 fully updated
AVG antivirus
Comodo firewall
Not much other extra software at this point